1. Field of the Invention
The present invention relates to a method for recording information onto a recording medium, and in particular to an information recording method and apparatus which is capable of improving a recording density of an optical recording medium.
2. Description of the Prior Art
Generally, a CD (Compact Disc) recording and/or reproducing apparatus records and/or reproduces information by irradiating a laser light beam onto an optical recording medium. The optical recording medium can be divided into a reproduction only disc and a recordable disc.
Recordable data is recorded on the compact disc as an EFM (Eight to Fourteen Modulation) frame of a 588 channel bit unit. One block including 98-number of EFM frames forms a sub-code frame as a basic unit capable of performing addressing. Herein, the sub-code frame is a minimum unit of time information and includes main channel data of 2352 byte.
The CD recording and/or reproducing apparatus performs random-access of information on the basis of a Q-code as a time code format included in the sub-code frame. The CD recording and/or reproducing apparatus such as a CD-R (CD-Recordable), a CD-RW (CD Re-Writable) will now be described with reference to accompanying FIG. 1.
FIG. 1 is a waveform diagram illustrating an ATIP (Absolute Time In Pre-groove) frame recorded as a wobble signal onto an optical recording medium in accordance with the prior art.
As depicted in FIG. 1, the CD recording and/or reproducing apparatus in accordance with the prior art records user information onto a wobbled groove track 103 as a pit 102 corresponding to binary information. A wobbled land track 101 is formed between the wobbled groove tracks. A wobble signal is preformatted on the both sides of wobbled groove track 103 with a certain cycle, the wobble signal controls a rotation velocity of a spindle motor (not shown) and is used as a reference signal generating a recording channel clock signal. In addition, ATIP (Absolute Time In Pre-groove) information capable of performing a physical addressing can be recorded by converting the wobble signal preformatted on the both sides of the wobbled groove track 103 into a carrier signal. Herein, a basic unit of the recorded ATIP information is an ATIP frame, one ATIP frame corresponds to a 294-wobble cycle of the wobble signal recorded on the both sides of wobbled groove track 103. A frame synchronous signal (Synch) is recorded on a start position of the ATIP frame, ID (IDentifier) information and a CRC (Cyclic Redundancy Check) code as an ECC (Error Correction Code) are recorded in the ATIP frame.
The frame synchronous signal (Synch) is recorded from a frame start to a 28-wobble cycle in the total 294 wobble cycle of the ATIP frames, the ID code and ECC are recorded on the rest of the wobble cycle. Herein, the ID code is a time code described as minute (MM):second (SS):frame(FF), and the time code is time information of a sub-code frame.
Meanwhile, in recording of user information, a sub-code frame is recorded so as to correspond to a preformatted ATIP frame one-to-one. One sub-code frame includes 588×98 number of channel bits. In addition, in recording of user information, the sub-code frame requires a write channel clock signal corresponding to 196-times of a 294 wobble cycle of the ATIP frame in order to perform sampling of recordable data. Hereinafter, an ATIP (Absolute Time In Pre-groove) information pre-format apparatus will now be described with reference to accompanying FIG. 2.
FIG. 2 is a block diagram illustrating the ATIP information pre-format apparatus in accordance with the prior art.
As depicted in FIG. 2, the ATIP (Absolute Time In Pre-groove) information pre-format apparatus in accordance with the prior art includes a clock generator 201 generating a clock signal of 44.1 kHz, a second frequency divider 202 outputting a carrier signal by being inputted the clock signal of 44.1 kHz, a first frequency divider 204 generating a bi-phase clock signal (PLCK) by being inputted the clock signal of 44.1 kHz, a bi-phase modulator 205 generating a DPS (Dual Phase Signal) by converting a channel bit stream (PCHB) from an input line 206 by the bi-phase clock signal (PCLK), and a frequency modulator 203 being inputted the carrier signal and DPS (Dual Phase Signal), frequency-modulating the DPS and outputting it. Herein, the channel bit stream (PCHB) is generated by channel-coding the ATIP information, it includes an ATIP frame synchronous signal (Synch), an ATIP ID (IDentification) code and an ECC (Error Correction Code). The ATIP ID code includes address information indicating a physical position of an optical disc and additional disc management information. Hereinafter, the operation of the ATIP pre-format apparatus in accordance with the prior art will now be described.
First, the second frequency divider 202 generates a carrier signal (fc) of 22.05 kHz by dividing a clock signal of 44.1 kHz by 2.
The first frequency divider 204 generates a bi-phase clock signal (PCLK) of 6.3 kHz by dividing the clock signal of 44.1 kHz from the clock generator 201 by 7.
The bi-phase modulator 205 generates a DPS (Dual Phase Signal) by converting the channel bit stream (PCHB) from the input line 206 with the bi-phase clock signal (PCLK). Herein, the DPS is frequency-converted by the frequency modulator 203 and is outputted through an output line 207. Accordingly, a wobble signal preformatted on the optical recording medium is FM-converted in a range of ±1 kHz in a center frequency of 22.05 kHz. Hereinafter, the CD recording and/or reproducing apparatus in accordance with the prior art will now be described with reference to accompanying FIG. 3.
FIG. 3 is a block diagram illustrating the CD recording and/or reproducing apparatus in accordance with the prior art.
As depicted in FIG. 3, a reproduction processing unit of the CD recording and/or reproducing apparatus in accordance with the prior art includes an optical pickup 301 outputting a push-pull signal, a RF (Radio Frequency) signal processing unit 302 generating a high frequency signal by signal-processing the push-pull signal, a demodulation/sub-code detecting unit 303 generating reproduction data by being inputted the high frequency signal, and a CIRC (Cross Interleaved Reed-Solomon) decoder 304 correcting errors of the reproduction data by a EFM (Eight to Fourteen Modulation) frame and outputting it. Hereinafter, the operation of the reproduction processing unit of the CD recording and/or reproducing apparatus in accordance with the prior art will now be described.
First, the RF signal processing unit 302 generates a high frequency signal by signal-processing the push-pull signal outputted from the optical pickup 301.
The demodulation/sub-code detecting unit 303 generates reproduction data by amplifying, equalizing and demodulating the high frequency signal from the RF signal processing unit 302.
The CIRC decoder 304 corrects errors of the reproduction data by the EFM frame.
In the meantime, a record processing unit of a recordable CD recording and/or reproducing apparatus in accordance with the prior art includes an optical pickup 301 outputting a push-pull signal, a wobble signal detecting unit 308 detecting a wobble signal by passing the push-pull signal through a carrier signal bandwidth, an ATIP (Absolute Time In Pre-groove) decoder 309 restoring ATIP (Absolute Time In Pre-groove) information as a physical address by using the wobble signal and generating a flag signal (ID-FLAG), a CIRC encoder 307 inserting an error correction code into inputted recordable data, a modulation/sub-code inserting unit 306 modulating the recordable data into an EFM (Eight to Fourteen Modulation) frame by sampling it with a write channel clock signal (WRT-CLK) and inserting an inputted sub-code into the EFM frame, a laser power controller 305 controlling a laser diode of the optical pickup 301 in accordance with a record channel signal from the modulation/sub-code inserting unit 306, and a microcomputer 310 generating a record start signal (WRT-ON) by synchronizing with the flag signal (ID-FLAG) from the ATIP decoder 309 and generating a sub-code by using an ID code. Hereinafter, the operation of the recordable CD recording and/or reproducing apparatus in accordance with the prior art will now be described.
First, the wobble signal detecting unit 308 detects a wobble signal by bandwidth-passing a push-pull signal outputted form the optical pickup 121 through a carrier signal bandwidth of 22.05 kHz. In more detail, as depicted in FIG. 4, the wobble signal detecting unit 308 is constructed with a BPF (Band Pass Filter) 401 and detects the wobble signal by bandwidth-passing the push-pull signal outputted form the optical pickup 301 through the carrier signal bandwidth of 22.05 kHz.
The ATIP decoder 309 restores ATIP information as a physical address by using the wobble signal form the wobble signal detecting unit 308. The ATIP decoder 309 generates an ID (IDentification) code as time information of minute:second:frame, an ID code error discrimination signal (ID-OK) indicating an error of the ID code, and a flag signal (ID-FLAG) in detecting of ATIP frame synchronous signal (Synch). In addition, the ATIP decoder 309 generates a write channel clock signal (WRT-CLK) for sampling recordable data. Hereinafter, the construction of the ATIP decoder 309 will now be described in detail with reference to accompanying FIG. 4.
FIG. 4 is a detailed block diagram illustrating the ATIP decoder 309 as shown at FIG. 3.
As depicted in FIG. 4, the ATIP decoder 309 includes a slicer 402 being inputted the wobble signal, a PLL (Phase Lock Loop) generating a write channel clock signal (WRT-CLK) by contacting to an output end of the slicer 402, a frequency demodulator 405 frequency-demodulating an output signal of the slicer 402, a bi-phase channel demodulator 407 restoring an output signal of the frequency demodulator 405 as bi-phase channel data, a decoder & latch 408 decoding an ID code of the bi-phase channel data, and a synchronous signal detecting unit 406 detecting a frame synchronous (Synch) signal from an output signal of the frequency demodulator 405. Herein, the PLL includes a phase comparator & LPF (Low Pass Filter) 403 contacted to the output end of the slicer 402, a VCO (Voltage Control Oscillator) 404 contacted to the phase comparator & LPF 403 so as to form a closed-loop, a fourth frequency divider 410 lowering a frequency of the write channel clock signal (WRT-CLK) by dividing the write channel clock signal (WRT-CLK) by 98, a third frequency divider 409 dividing an output signal of the fourth frequency divider 410 by 2, a fifth frequency divider 411 dividing an output signal of the third frequency divider 410 by 7, and a sixth frequency divider 412 dividing an output signal of the fifth frequency divider 411 by 2 and outputting it. The operation of the ATIP decoder 309 in accordance with the prior art will now be described with reference to accompanying FIGS. 3 and 4.
First, the slicer 402 generates a carrier signal by slicing a wobble signal outputted from the BPF (Band Pass Filter) 401 with a certain slice level.
The phase comparator & LPF 403 compares a phase of the carrier signal outputted form the slicer 402 with a phase of an output signal of the second frequency divider 409 and generates a control signal corresponding to the phase difference.
The VCO 404 generates the write channel clock signal (WRT-CLK) by varying a frequency of an oscillation frequency in accordance with the control signal outputted from the phase comparator & LPF 403. Herein, the write channel clock signal (WRT-CLK) is maintained as 4.3218 MHz 196-times increased from the carrier signal (fc=22.05 kHz) of the wobble signal.
The fourth frequency divider 410 lowers a frequency of the write channel clock signal (WRT-CLK) as 44.1 kHz by dividing the write channel clock signal (WRT-CLK) by 98. In addition, the output signal of the fourth frequency divider 410 is inputted to the phase comparator & LPF 403 as a frequency of 22.05 kHz after being divided by 2 by the third frequency divider 409 and is restored as a bi-phase clock signal (PCLK) of 6.3 kHz by being divided by 7 by the fifth frequency divider 411.
The frequency demodulator 405 demodulates the ATIP information by sampling a carrier signal outputted form the slicer 402 in accordance with the write channel clock signal (WRT-CLK).
The synchronous signal detecting unit 406 detects a frame synchronous signal (Synch) in an output signal of the frequency demodulator 405. The frame synchronous signal (Synch) detected from the synchronous signal detecting unit 406 is outputted to the decoder & latch 408, and is outputted to the microcomputer 310 as a flag signal (ID FLAG) indicating a start of the ATIP frame.
The bi-phase demodulator 407 demodulates the bi-phase signal by the bi-phase clock signal (PCLK) inputted from the fifth frequency divider 411 and provides it to the decoder & latch 408.
The decoder & latch 408 restores an ID code from a data channel clock signal (DCLK) that the bi-phase clock signal (PCLK) is divided by 2 and a channel bit stream outputted from the bi-phase demodulator 407 by the frame synchronous signal (Synch), and performs an error correction about the ID code. The ID code detected by the decoder & latch 408 and flag signal (ID FLAG) indicating the error correction are outputted to the microcomputer 310.
The microcomputer 310 generates a record start signal (WRT-ON) by synchronizing with the flag signal (ID FLAG) from the ATIP decoder 309 and generates a sub-code by using the ID code.
The CIRC encoder 307 inserts an error correction code into the inputted recordable data. The modulation/sub-code inserting unit 306 modulates the recordable data from the CIRC encoder 307 into an EFM code by sampling it with the write channel clock signal (WRT-CLK) and inserts the sub-code outputted from the microcomputer 310 into an EFM frame.
The laser power controller 305 controls a laser diode of the optical pickup 310 in accordance with a record channel signal from the modulation/sub-code inserting unit 306.
In recording of user information, the microcomputer 310 generates the record start signal (WRT-ON) by detecting a record start position (MM:SS:FF (START)) of an ATIP frame preformatted on the optical disc in the ID code described as minute:second:frame time information. The modulation/sub-code inserting unit 306 generates a record channel signal by synchronizing with a frame synchronous signal, namely, a flag signal (ID FLAG) starting an ATIP (Absolute Time In Pre-groove) frame.
In the meantime, when a record end position (MM:SS:FF (END)) is detected, the microcomputer 310 cuts off the record start signal (WRT-ON). Herein, the modulation/sub-code inserting unit 306 ends the record channel signal generation by synchronizing with the flag signal (ID FLAG).
As described above, in a recordable optical recording medium such as a CD-R (Compact Disc-Recordable), a CD-RW (Compact Disc Re-Writable), a sub-code frame including user information is recorded so as to correspond one-to-one to an ATIP frame preformatted onto an optical disc. Accordingly, a physical length of sub-code frame is equal to a physical length of an ATIP frame. And, main channel data as the user information is recorded as 2352 byte per one ATIP frame (Absolute Time In Pre-groove).
FIG. 5 is a waveform diagram illustrating input/output of the record processing unit of the CD recording and/or reproducing apparatus as shown at FIG. 3. In more detail, FIG. 5 illustrates an input/output of a flag signal (ID FLAG), an ID code error discrimination signal (ID-OK) indicating an error of an ID code, an ID code described as time information of minute:second:frame, a record start signal (WRT-ON), and a write signal recording user information.
Recently, a recording density of an optical recording medium has been improved in accordance with a development of a blue laser and increase of a diameter of an object lens. However, information has to be recorded by corresponding one-to-one to a physical length of an ATIP frame preformatted onto an optical disc by a unit sub-code frame, accordingly it is difficult to improve a recording density more.
In the meantime, in an information recording method and apparatus of a Korea patent No. 0253805, a technique varying a length of a unit record region by generating a logical address different from a physical address preformatted onto an optical disc is represented. However, in the represented recording method, a write channel clock signal which has to vary in accordance with a variable length of unit record regions is not provided accurately.
As described above, the information recording apparatus in accordance with the prior art has to record information so as to correspond one-to-one to a physical length of an ATIP (Absolute Time In Pre-groove) frame preformatted onto an optical disc by a unit sub-code frame, accordingly it is difficult to improve a recording density.
In addition, the information recording apparatus in accordance with the prior art can not provide accurately a write channel clock signal so as to vary in accordance with a variable length of a unit record region.